drm/amdgpu: support rom clockgating related function for NV family

Add functions to support enable/disable rom clock gating and get rom
clock gating status.

Signed-off-by: Likun Gao <[e-mail]>
Reviewed-by: Hawking Zhang <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/nv.c

···
 				state == AMD_CG_STATE_GATE);
 		adev->hdp.funcs->update_clock_gating(adev,
 				state == AMD_CG_STATE_GATE);
+		adev->smuio.funcs->update_rom_clock_gating(adev,
+				state == AMD_CG_STATE_GATE);
 		break;
 	default:
 		break;
···
 	adev->nbio.funcs->get_clockgating_state(adev, flags);
 
 	adev->hdp.funcs->get_clock_gating_state(adev, flags);
+
+	adev->smuio.funcs->get_clock_gating_state(adev, flags);
 
 	return;
 }

drivers/gpu/drm/amd/amdgpu/smuio_v11_0_6.c

···
 	return SOC15_REG_OFFSET(SMUIO, 0, mmROM_DATA);
 }
 
+static void smuio_v11_0_6_update_rom_clock_gating(struct amdgpu_device *adev, bool enable)
+{
+	u32 def, data;
+
+	/* enable/disable ROM CG is not supported on APU */
+	if (adev->flags & AMD_IS_APU)
+		return;
+
+	def = data = RREG32_SOC15(SMUIO, 0, mmCGTT_ROM_CLK_CTRL0);
+
+	if (enable && (adev->cg_flags & AMD_CG_SUPPORT_ROM_MGCG))
+		data &= ~(CGTT_ROM_CLK_CTRL0__SOFT_OVERRIDE0_MASK |
+			CGTT_ROM_CLK_CTRL0__SOFT_OVERRIDE1_MASK);
+	else
+		data |= CGTT_ROM_CLK_CTRL0__SOFT_OVERRIDE0_MASK |
+			CGTT_ROM_CLK_CTRL0__SOFT_OVERRIDE1_MASK;
+
+	if (def != data)
+		WREG32_SOC15(SMUIO, 0, mmCGTT_ROM_CLK_CTRL0, data);
+}
+
+static void smuio_v11_0_6_get_clock_gating_state(struct amdgpu_device *adev, u32 *flags)
+{
+	u32 data;
+
+	/* CGTT_ROM_CLK_CTRL0 is not available for APU */
+	if (adev->flags & AMD_IS_APU)
+		return;
+
+	data = RREG32_SOC15(SMUIO, 0, mmCGTT_ROM_CLK_CTRL0);
+	if (!(data & CGTT_ROM_CLK_CTRL0__SOFT_OVERRIDE0_MASK))
+		*flags |= AMD_CG_SUPPORT_ROM_MGCG;
+}
+
 const struct amdgpu_smuio_funcs smuio_v11_0_6_funcs = {
 	.get_rom_index_offset = smuio_v11_0_6_get_rom_index_offset,
 	.get_rom_data_offset = smuio_v11_0_6_get_rom_data_offset,
+	.update_rom_clock_gating = smuio_v11_0_6_update_rom_clock_gating,
+	.get_clock_gating_state = smuio_v11_0_6_get_clock_gating_state,
 };